1. Field of the Invention
The present invention relates to a washer and washing cycle control method thereof.
2. Discussion of the Related Art
Generally, a drum type washer has a configuration shown in FIG. 1 as follows.
Referring to FIG. 1, a tub 20 is fixed to an inside of a body 10. A drum 30 is rotatably installed within the tub 20 to be rotated by receiving a drive force of a BLDC (brushless direct current) motor 40 via belt 41. A plurality of baffles 31 are fixed to an inner circumference of the drum 30 to leave a predetermined distance from each other. And, the baffles 31 are operative in lifting a laundry upward within the drum 30.
A sensor hose 60 is connected to a bottom of the tub 20. And, a water level sensor 50 is provided to a tip of the sensor hose 60 to sense an amount of water supplied to the tub 20. The water level sensor 50 applies a signal of sensing the amount of water to a system control unit 70.
FIG. 2 is a block diagram of the system control unit 70 of the general drum type washer.
Referring to FIG. 2, the system control unit 70 consists of a converter 71 converting 220V AC voltage to DC voltage, an inverter unit 72 applying the DC voltage outputted from the converter 71 to the BLDC motor 40 as a power source according to a drive signal, a rotational speed sensing unit 73 sensing a rotational speed of the BLDC motor 40, a water level sensing unit 74 sensing a water level within the tub 20, a control unit 75 generating control signals according to various input signals of the water level sensing unit 74, the rotational speed sensing unit 73, and the like, and a gate drive unit 76 outputting drive signals according to the control signals outputted from the control unit 75.
A method of measuring a laundry amount in a drum type washer according to a related art is explained by referring to FIG. 3 and FIG. 4 as follows.
Referring to FIG. 3, once a washing cycle is initiated, water is supplied to the drum at a water level previously set up by a user.
The control unit 75 sends a gate drive control signal and a PWM (pulse width modulation) signal to drive the BLDC motor 40. In doing so, the control unit agitates the drum 40 in forward-to-reverse directions so that water can be evenly absorbed in the laundry.
After the water has been evenly absorbed in the laundry by agitating the drum 40 in the forward-to-reverse directions, the water level, as shown in FIG. 4, is lowered below the water level previously set up by the user.
If the water level is lowered below the previously set water level by the water absorption in the laundry, the control unit 75 decides whether a water re-supply is necessary.
If deciding that the water re-supply is necessary, the control unit 75 stops agitating the drum 30 in the forward-to-reverse directions. After having re-supplied water up to the previously set water level, the control unit 75 agitates the drum 30 again.
The control unit 75 repeatedly performs the above-explained procedure during a prescribed time t1 and counts the number of performing the water re-supply.
After the prescribed time t1 has passed, the control unit 75 decides the laundry amount of the laundry according to the counted number of performing the water re-supply. If the counted number is small, it is decided that the laundry amount is small. If the counted number is great, it is decided that the laundry amount is large.
A criteria of deciding the laundry amount according to the water re-supply number is determined via tests to be programmed in the control unit 75.
For instance, if the water re-supply number is smaller than ‘2’, it is decided that the laundry amount of the laundry is smaller than 2 kg. If the water re-supply number is greater than ‘7’, it is decided that the laundry amount of the laundry is greater than 5 kg.
However, the related art laundry amount deciding method is carried out in a manner of deciding the laundry amount using the water re-supply number after completion of supplying the water into the drum, whereby a washing time is fixed regardless of the laundry amount of the laundry as well as an amount of used water is almost identical.
Hence, a washing cycle time is unnecessarily taken so long as to waste power consumption. And, the amount of the used water is unnecessarily sufficient to waste water.